.body { 
  height: 100%;
  width: 200px;
  padding: 0 8px;
  overflow-y: auto;
  overflow-x: hidden;
}

mat-tree {
  height: 100%;
  width: 100%;
}

.mat-tree-node {
  &:hover {
    background-color: #e6ecf8;
    
    // 鼠标
    cursor: pointer;
  }
}
